title: Calreticulin transacetylase mediated upregulation of thioredoxin by 7,8-diacetoxy-4-methylcoumarin enhances the antioxidant potential and the expression of vascular endothelial growth factor in peripheral blood mononuclear cells.
abstract: Extensive research carried out in our group on polyphenolic acetates (PAs) substantiated the potential role of PAs in causing diverse biological and pharmacological actions. Our earlier investigations firmly established the calreticulin transacetylase (CRTAase) catalyzed activation of nitric oxide synthase (NOS) by PAs. In this report, we have studied the effect of 7,8-diacetoxy-4-methylcoumarin (DAMC, a model PA) and other acetoxy coumarins on the thioredoxin and VEGF expression in human peripheral blood mononuclear cells (PBMCs), with a view to substantiate our earlier observation that DAMC was a superb inducer of angiogenesis. Real time RT-PCR analysis revealed the enhanced expression of thioredoxin reductase (TRXR) and diminished expression of thioredoxin interacting protein (TRXIP) leading to the increased expression and activity of thioredoxin (TRX) in PBMCs due to the the action of DAMC. The fact that TRX activity of PBMCs was enhanced by various acetoxy coumarins in tune with their affinity to CRTAase as substrate, suggested the possible activation of TRX due to acetylation. The overexpression of thioredoxin was found to correlate with that of VEGF as proved by real time RT-PCR and VEGF -ELISA results, apart from the DAMC-caused enhanced production of NO acting as an inducer of VEGF. Moreover, the intracellular ROS levels were also found to be reduced drastically, by DAMC thus reducing the oxidative stress in cells. These observations strongly evidenced the crucial role of TRX in DAMC-induced tissue angiogenesis with the involvement of VEGF.
authors.affiliation: Department of Biochemistry, V.P. Chest Institute, University of Delhi, Delhi 110 007, India; Department of Chemistry, University of Delhi, Delhi 110 007, India.
authors.forename: Rini
authors.initials: R
authors.lastname: Joshi
authors.forename: Ajit
authors.initials: A
authors.lastname: Kumar
authors.forename: Sushma
authors.initials: S
authors.lastname: Manral
authors.forename: Rajesh
authors.initials: R
authors.lastname: Sinha
authors.forename: Shvetambri
authors.initials: S
authors.lastname: Arora
authors.forename: Anju
authors.initials: A
authors.lastname: Sharma
authors.forename: Sanjay
authors.initials: S
authors.lastname: Goel
authors.forename: Namita
authors.initials: N
authors.lastname: Kalra
authors.forename: Suvro
authors.initials: S
authors.lastname: Chatterji
authors.forename: Bilikere S
authors.initials: BS
authors.lastname: Dwarakanath
authors.forename: Diwan S
authors.initials: DS
authors.lastname: Rawat
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Depass
authors.forename: Vishwajeet
authors.initials: V
authors.lastname: Rohil
authors.forename: Daman
authors.initials: D
authors.lastname: Saluja
authors.forename: Virinder S
authors.initials: VS
authors.lastname: Parmar
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Prasad
authors.forename: Hanumantharao G
authors.initials: HG
authors.lastname: Raj
mesh_terms: D000107:Acetylation; D000123:Acetyltransferases / Q000378:metabolism*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003374:Coumarins / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013880:Thioredoxin-Disulfide Reductase / Q000235:genetics / Q000378:metabolism; D013879:Thioredoxins / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: C114369:7,8-diacetoxy-4-methylcoumarin; D000975:Antioxidants; D002352:Carrier Proteins; D003374:Coumarins; D017382:Reactive Oxygen Species; C486715:TXNIP protein, human; D042461:Vascular Endothelial Growth Factor A; D013879:Thioredoxins; D013880:Thioredoxin-Disulfide Reductase; D000123:Acetyltransferases; C539012:calreticulin transacetylase, human
keywords: Calreticulin transacetylase; Nitric-oxide synthase; Thioredoxin; Thioredoxin interacting protein; Thioredoxin reductase; Vascular endothelial growth factor